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 A259919 Number of n X n upper triangular matrices (m_{i,j}) of nonnegative integers with 2 = Sum_{j=h..n} m_{h,j} - Sum_{i=1..h-1} m_{i,h} for all h in {1,...,n}. 1
 1, 1, 3, 22, 351, 11275, 689146, 76718466, 15016410213, 5018597151979, 2793390337774000, 2534303740130716491, 3677548139455638020060, 8393668597786379602398164, 29683833854927200499142474520, 160463839044675821511377573062150, 1309702228155431081923017737636343876 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS a(n) counts generalized Tesler matrices.  For the definition of Tesler matrices see A008608. LINKS EXAMPLE a(2) = 3: [1,1; 0,3], [2,0; 0,2], [0,2; 0,4]. MAPLE b:= proc(n, i, l) option remember; (m-> `if`(m=0, 1,       `if`(i=0, b(l[1]+2, m-1, subsop(1=NULL, l)), add(       b(n-j, i-1, subsop(i=l[i]+j, l)), j=0..n))))(nops(l))     end: a:= n-> b(2, n-1, [0\$(n-1)]): seq(a(n), n=0..10); CROSSREFS Column k=2 of A259844. Cf. A008608. Sequence in context: A193193 A099750 A219268 * A275366 A196734 A271849 Adjacent sequences:  A259916 A259917 A259918 * A259920 A259921 A259922 KEYWORD nonn AUTHOR Alois P. Heinz, Jul 08 2015 STATUS approved

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Last modified February 26 20:23 EST 2020. Contains 332295 sequences. (Running on oeis4.)